Conventional methods for the transmission of a digital data stream require at least three lines per direction for the data exchange, i.e. a total of at least six lines in order to transmit the data stream including information about a data clock and/or the start of data frames. A high number of lines disadvantageously requires the provision of a corresponding number of connection units or connection pins on a layout of a data stream receiver and/or a data stream transmission unit. For reliable data transmission, it is necessary in accordance with conventional methods also to provide at least one further line for feeding the data clock, in addition to a data input line and a data output line.
The data clock is necessary, for example, to synchronize a PLL, to output a data stream in data stream units or data blocks, and to reliably receive corresponding data streams.
During a transmission of a digital data stream, the data stream is divided into so-called data stream units, comprising at least one synchronization word and a data block with a defined number of data bits. In addition to determining the data clock, it is necessary in many areas of application to determine the start of the data frames and/or the start of data superframes. According to conventional methods for the transmission of a digital data stream, this necessitates further lines and, associated with this, corresponding connection units of a data stream receiver/data stream transmitter. This disadvantageously increases the number of connection units further.